Preparation Of Silica-based Mesoporous Materials And Their Use In Treatment Of Phenol-containing Wastewater By Adsorption

With the environment pollution being more and more worst, especially the lacking and pollution of water resource, more attention is paid to environmental protection issues and water quality. It's hard for some traditional water treatment ways and processes to reach people's requirement because of their limitation. For the big specific area and powerful adsorption capability of mesoporous materials, it can be used as adsorbent to treat the phenol-containing wastewater.The silica-based mesoporous materials are synthesized under normal atmospheric with CTAB as surfactant, TEOS as silica source and hydrochloric acid as activator. The pore sizes distribution of mesoporous materials are adjusted by organic assistant reagent TMB(l,3,5-three toluol).The materials after and before TMB addition are characterized through XRD,IR and Na adsorption. The results show that the materials have regular hexagonal mesoporous structure. But the structure and pore sizes are more regular and bigger after TMB is added.The adsorption effects are researched in different time, different concentration, different temperature and different pH values with the synthesized materials as adsorbent to treat phenol-containing wastewater. The adsorption experiments show that the calcined materials have greater adsorption efficiency. The adsorption efficiency is better after TMB is added. The adsorption efficiency can reach 98% and saturated adsorption quantity can reach 313 mg-g-1 when TMB is added properly.The adsorption experiments with mesoporous materials as adsorbent to treat phenol-containing wastewater at different temperature show that the adsorption efficiency becomes lower and lower with the temperature rising. Because the phenol solubility increases with temperature, the solvation effect of water molecule to phenol affects the interaction power formulation between hydrophobe and phenol and results in the adsorption quantity being lower.The adsorption experiments with mesoporous materials as adsorbent to treat phenol-containing wastewater at different pH values show that the adsorption efficiency becomes lower and lower with increasing pH. It's because of phenol belonging to weak acidic compound. There exists partial ionization for phenol at certain pH values. It shows two different states, ionic and nonionic in solution. It's useful for adsorption when the pH values decreases. With the pH value rising ,the ionization of phenol increases. So adsorption quantity reduces markedly.The mesoporous materials are regenerated with 1% NaOH solution afteradsorption. The results show that the first regeneration efficiency of all materials is above 95%. The regeneration requirement can be satisfied.